Hi, is it possible to filter all email from a domain if the address is a wildcard, as in *@mydomain.com, but not if its info@mydomain.com? I have a personal website and any email sent to my domain gets through - I only want email from the one email address I created.

In Filters (F4) make a filter for incoming messages.
In Filter messages for, make sure to select that one particular account.
Search Recipients for info@mydomain.com, and choose "match only if not found", and in Perform, choose any action you wish to do with those that do not come to info@mydomain.com.

I'd suggest first make it to send those filtered messages (via Perform) to a special mailbox where you can inspect them (or at least Thrash or Junk), and only once you know that filter works well for you, you can set it to delete them automatically. Just to be on the safe side.